Long-term Dietary Supplementation Research Articles

Effect of long-term dietary supplementation with clinoptilolite on performance and selected serum biochemical values in dairy goats

To determine the effect of dietary supplementation with clinoptilolite on health and production as well as serum concentrations of fat-soluble vitamins, macroelements and trace elements, and activities of hepatic enzymes in dairy goats. 72 Saanen-cross dairy goats. Goats were randomly assigned to 1 of 2 groups. The clinoptilolite group (n = 36) received concentrate feed, of which 2.5% contained clinoptilolite; the control group (36) received unsupplemented feed. The experiment began 8 weeks before parturition and continued to the beginning of the next nonlactating period (280 days of lactation). At the day of parturition, kids were weighed. Milk yields were recorded at day 60 of lactation and thereafter at monthly intervals. Milk percentages of fat, protein, and lactose and somatic cell count (SCC) were evaluated at the same points. Blood samples were obtained at the beginning of the experiment, the day of parturition, and thereafter at monthly intervals to measure serum concentrations of fat-soluble vitamins, macroelements and trace elements, and activities of hepatic enzymes. Birth weights of triplets and quadruplets were significantly higher in clinoptilolite-treated goats versus control goats. Milk fat percentage was significantly higher and SCC was significantly lower in clinoptilolite-treated goats, compared with respective values in control goats. However, no changes in serum concentrations of any variable were detected. In the context of this experiment, clinoptilolite supplementation of concentrate feed at 2.5% improved milk fat percentage in dairy goats, without adverse effects on the serum variables evaluated. Furthermore, the reduction of SCC achieved with clinoptilolite supplementation provided some evidence of improved milk hygiene.

Resveratrol preserves cerebrovascular density and cognitive function in aging mice

Resveratrol, a natural polyphenol abundant in grapes and red wine, has been reported to exert numerous beneficial health effects. Among others, acute neuroprotective effects of resveratrol have been described in several models of neurodegeneration, both in vitro and in vivo. In the present study we examined the neuroprotective effects of long-term dietary supplementation with resveratrol in mice on behavioral, neurochemical and cerebrovascular level. We report a preserved cognitive function in resveratrol-treated aging mice, as shown by an enhanced acquisition of a spatial Y-maze task. This was paralleled by a higher microvascular density and a lower number of microvascular abnormalities in comparison to aging non-treated control animals. We found no effects of resveratrol supplementation on cholinergic cell number or fiber density. The present findings support the hypothesis that resveratrol exerts beneficial effects on the brain by maintaining cerebrovascular health. Via this mechanism resveratrol can contribute to the preservation of cognitive function during aging.

Tissue Distribution of Quercetin in Pigs after Long-Term Dietary Supplementation

Although the flavonol quercetin is intensively investigated, our knowledge about its bioavailability and possible target organs is far from being complete. The aim of this study was to check the potential of quercetin to accumulate in various tissues after long-term dietary treatment compared with a single treatment with flavonol. Pigs ingested either a single dose of quercetin aglycone (25 mg/kg body weight; Expt. 1) or received the flavonol twice a day at the same dose mixed into their regular meals (i.e 50 mg·kg −1·d −1) for 4 wk (Expt. 2). In both experiments, we took plasma and tissue samples 90 min after the final meal and analyzed them using HPLC. Additionally, the specific activity of the enzyme β-glucuronidase was measured in selected tissues. Higher flavonol concentrations than in plasma were found in only the liver (Expt. 1) or the intestinal wall and kidneys (Expt. 2). All tissues except blood plasma contained a variable amount of deconjugated quercetin in the range of 30–100% of total flavonols. However, the specific β-glucuronidase activity was not correlated with the proportions of deconjugated flavonols in the various tissues. Long-term dietary intake of the flavonol did not lead to a greater accumulation in any tissue compared with the single treatment. Flavonol concentrations only exceeded the plasma concentration within organs involved in its metabolism and excretion, including liver, small intestine, and kidneys.

Complementary Feeding With Fortified Spread and Incidence of Severe Stunting in 6- to 18-Month-Old Rural Malawians

To compare growth and incidence of malnutrition in infants receiving long-term dietary supplementation with ready-to-use fortified spread (FS) or micronutrient-fortified maize-soy flour (likuni phala [LP]). Randomized, controlled, single-blind trial. Rural Malawi. A total of 182 six-month-old infants. Participants were randomized to receive 1 year of daily supplementation with 71 g of LP (282 kcal), 50 g of FS (FS50) (256 kcal), or 25 g of FS (FS25) (130 [corrected] kcal). Weight and length gains and the incidences of severe stunting, underweight, and wasting. Mean weight and length gains in the LP, FS50, and FS25 groups were 2.37, 2.47, and 2.37 kg (P = .66) and 12.7, 13.5, and 13.2 cm (P = .23), respectively. In the same groups, the cumulative 12-month incidence of severe stunting was 13.3%, 0.0%, and 3.5% (P = .01), of severe underweight was 15.0%, 22.5%, and 16.9% (P = .71), and of severe wasting was 1.8%, 1.9%, and 1.8% (P > .99). Compared with LP-supplemented infants, those given FS50 gained a mean of 100 g more weight and 0.8 cm more length. There was a significant interaction between baseline length and intervention (P = .04); in children with below-median length at enrollment, those given FS50 gained a mean of 1.9 cm more than individuals receiving LP. One-year-long complementary feeding with FS does not have a significantly larger effect than LP on mean weight gain in all infants, but it is likely to boost linear growth in the most disadvantaged individuals and, hence, decrease the incidence of severe stunting.

Gender differences in the modulation of cardiac gene expression by dietary conjugated linoleic acid isomersThis paper is one of a selection of papers published in this Special Issue, entitled The Cellular and Molecular Basis of Cardiovascular Dysfunction, Dhalla 70th Birthday Tribute.

In an earlier study, we showed that dietary conjugated linoleic acid (CLA) isomers can exert differential effects on heart function in male and female rats, but the underlying mechanisms for these actions are not known. Cardiomyocyte Ca2+ cycling is a key event in normal cardiac contractile function and defects in Ca2+ cycling are associated with cardiac dysfunction and heart disease. We therefore hypothesized that abnormalities in the sarcolemmal (SL) and sarcoplasmic reticulum (SR)-mediated regulation of intracellular Ca2+ contribute to altered cardiac contractile function of male and female rats owing to dietary CLA isomers. Healthy male and female Sprague-Dawley rats were fed different CLA isomers, (cis-9, trans-11 (c9,t11) and trans-10, cis-12 (t10,c12)) individually and in combination (50:50 mix as triglyceride or fatty acids) from 4 to 20 weeks of age. We determined the mRNA levels of sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA) 2a, ryanodine receptor, phospholamban, calsequestrin, Na+-Ca2+-exchanger (NCX), and L-type Ca2+ channel in the left ventricle (LV) by RT-PCR. The SR function was assessed by measurement of Ca2+-uptake and -release. Significant gender differences were seen in the LV NCX, L-type Ca2+ channel, and ryanodine receptor mRNA expression levels in control male and female rats. Dietary CLA isomers in the various forms induced changes in the mRNA levels of SERCA 2a, NCX, and L-type Ca2+ channel in the LV of both male and female hearts. Whereas protein contents of the Ca2+ cycling proteins were altered, changes in SR Ca2+-uptake and -release were also detected in both male and female rats in response to dietary CLA. The results of this study demonstrate that long-term dietary supplementation can modulate cardiac gene expression and SR function in a gender-related manner and may, in part, contribute to altered cardiac contractility.

Chronic administration of UMP ameliorates the impairment of hippocampal-dependent memory in impoverished rats.

We have previously shown that chronic, but not acute, dietary supplementation with CDP-choline prevents the hippocampal-dependent memory deficits manifested by aged rats and by rats reared under impoverished environmental conditions. In rats, dietary CDP-choline is rapidly metabolized into cytidine and choline; the cytidine is then readily converted to uridine, which enters the brain and, via conversion to UTP and CTP, increases brain levels of membrane phosphatides. Hence, we have assessed whether administering a uridine source (UMP) instead of CDP-choline can also ameliorate the memory deficits in rats reared under impoverished environmental conditions. At weaning, 32 male Sprague-Dawley rats were exposed to either enriched (EC) or impoverished (IC) conditions for 3 mo. Concurrently, IC and EC rats were given access to either a control diet or a diet supplemented with 0.1% UMP. Rats were then assessed for learning and memory skills using 2 versions of the Morris water maze, the hidden platform version that assesses hippocampal-dependent cognitive memory processing, and the visible platform version that assesses striatal-dependent habit memory. As expected, exposure to the impoverished environment impaired hippocampal-dependent, but not striatal-dependent learning and memory. Supplementation with UMP prevented this cognitive dysfunction, as had been observed with supplemental CDP-choline. These results suggest that IC rats do not use and/or remember their spatial strategies for task solving as well as EC rats, and that long-term dietary supplementation with UMP alleviates this dysfunction.

The silicon link between aluminium and Alzheimer's disease

Christopher Exley and colleagues report in this issue of JAD [15] the results of a clinical study showing that drinking silicic acid (Si(OH)4)-rich mineral water for five days significantly reduces the urinary excretion of aluminium, but not iron in Alzheimer disease (AD) patients. The authors argue that the long-term dietary supplementation of Si(OH)4 might qualify as a non-invasive therapy for reducing the body burden of aluminium in AD. This study opens a new chapter of the investigations of J. Derek Birchall’s hypothesis of a silicon link between aluminium and AD, for it offers a direct demonstration of the efficacy of dietary silica supplementation in increasing the excretion of aluminium in AD. But what can we expect in terms of therapeutic effects from stimulating the aluminium urinary excretion in AD? We will briefly discuss here the context and implications of this study. The systematic interest for the utilization of silicon in medicine can be traced back to the late nineteenth century, when the emulation of physiologists for research on this element led Luis Pasteur to predict that silicon reserved important therapeutic applications in many human diseases. However, the recognition of silicon as an essential trace element came only in 1972 when two reports showed that dietary silicon deprivation in chicks and rats was associated with retarded growth and bone deformities [6,28]. Subsequent research has established that silicon is indeed important for the calcification of bone and cartilage, and it may be thus involved in disorders characterized by an imbalance between bone formation and resorption (e.g., osteoporosis), joint disorders (e.g., osteoarthritis), and even heart disease and aging (for review see [27]). In contrast to the rather straightforward demonstrations of the roles of silicon in bone and connective tissue homeostasis, the link between silicon and neuropathology and particularly AD was put forward via the aluminium hypothesis in AD. Taking account of the high chemical affinity of silicon for aluminium, and the typical inverse relation between the concentrations of aluminium and silicon in water supplies, the British chemist J.D. Birchall suggested that silicon might mediate the effect of aluminium from drinking water on AD incidence [2,3]. This suggestion was partly based on an earlier finding reported by Birchall, Exley and coworkers that Si(OH)4 in water protected salmon against fatal ionoregulatory, osmoregulatory and respiratory dysfunctions caused by toxic aluminium binding to the gill epithelium [4,14]. Following Birchall’s suggestion, several epidemiological studies reviewed in [19] (see also [20]) indicated that the protective effect of silicon from drinking water against AD was only modest. Nonetheless, in spite of this apparent rebuttal of Birchall’s hypothesis, the silicon link between aluminium and AD continued to be supported on other lines of research. For instance, silicon, more specifically as silica oligomers [21], reduced by several folds the gastrointestinal absorption of aluminium in humans [11] and increased its urinary excretion [1], as originally suggested [2]; high serum silicon was shown

Arachidonic acid preserves hippocampal neuron membrane fluidity in senescent rats

Previous studies indicate that long-term dietary supplementation with arachidonic acid (AA) in 20-month-old rats (OA) effectively restores performance in a memory task and the induction of long-term potentiation in the hippocampus to the level of young control animals (YC). The present study examined protein mobility using the live cell imaging technique “Fluorescent Recovery After Photobleaching (FRAP)” in YC, old control (OC) and OA neurons in hippocampal slice preparations. Three measures; mobile fraction (Mf), diffusion constant (D) and time constant (τ), were estimated among YC, OC and OA. Each of these parameters was significantly different between OC and YC, suggesting that membrane fluidity is lower in OC than in YC. In contrast, D and τ were comparable in OA and YC, indicating that hippocampal neuronal membranes supplemented with AA were more fluid than those in OC, whereas the fraction of diffusible protein in the bleached region remained smaller than in YC. Long-term administration of AA to senescent rats might help to preserve membrane fluidity and maintain hippocampal plasticity.

Antioxidant N-acetyl cysteine reduces incidence and multiplicity of lymphoma in Atm deficient mice

Hereditary human disorder ataxia telangiectasia (AT) is characterized by an extremely high incidence of lymphoid malignancies, neuromotor dysfunction, immunodeficiency and radiosensitivity. Cells from AT patients show genetic instability and a continuous state of oxidative stress. We examined the effect of long-term dietary supplementation with the thiol-containing antioxidant, N-acetyl- l-cysteine (NAC), on survival and cancer formation in Atm (AT-mutated) deficient mice, used as an animal model of AT. NAC was chosen because it is well-tolerated in animals and humans. It can be used by the oral route and for long-term at high concentrations. In addition, NAC suppresses carcinogenesis-associated biological markers in Atm deficient mice, such as DNA deletions and oxidative DNA damage (R. Reliene, E. Fischer, R.H. Schiestl, Effect of N-acetyl cysteine on oxidative DNA damage and the frequency of DNA deletions in atm-deficient mice, Cancer Res. 64 (2004) 5148–5153). In this study, NAC significantly increased the lifespan and reduced both the incidence and multiplicity of lymphoma in Atm deficient mice. The life span increased from 50 to 68 weeks and the incidence of lymphoma decreased by two-fold (76.5% versus 37.5%). Moreover, in mice with lymphoma, multiplicity of tumors decreased from 4.6 to 2.8 tumors per mouse. Thus, dietary supplementation with NAC may turn out to be protective against lymphomagenesis in AT patients.

Serotonin Derivatives, Major Safflower (Carthamus tinctorius L.) Seed Antioxidants, Inhibit Low-Density Lipoprotein (LDL) Oxidation and Atherosclerosis in Apolipoprotein E-Deficient Mice

The effects of defatted safflower seed extract and its phenolic constituents, serotonin derivatives, on atherosclerosis were studied. Ethanol-ethyl acetate extract of safflower seeds (SSE) inhibited low-density lipoprotein (LDL) oxidation induced in vitro by an azo-containing free-radical initiator V70 or copper ions. Two serotonin derivatives [N-(p-coumaroyl)serotonin, CS; N-feruloylserotonin, FS] and their glucosides were identified as the major phenolic constituents of the extract. The study with chemically synthesized materials revealed that a majority of the antioxidative activity of SSE was attributable to the aglycones of these two serotonin derivatives. Orally administered CS and FS suppressed CuSO(4)-induced plasma oxidation ex vivo. Long-term (15 week) dietary supplementation of SSE (1.0 wt %/wt) and synthetic serotonin derivatives (0.2-0.4%) significantly reduced the atherosclerotic lesion area in the aortic sinus of apolipoprotein E-deficient mice (29.2-79.7% reduction). The plasma level of both lipid peroxides and anti-oxidized LDL autoantibody titers decreased concomitantly with the reduction of lesion formation. Serotonin derivatives were detected as both intact and conjugated metabolites in the plasma of C57BL/6J mice fed on 1.0% SSE diet. These findings demonstrate that serotonin derivatives of SSE are absorbed into circulation and attenuate atherosclerotic lesion development possibly because of the inhibition of oxidized LDL formation through their strong antioxidative activity.

Effects of long-term dietary supplementation with clinoptilolite on incidence of parturient paresis and serum concentrations of total calcium, phosphate, magnesium, potassium, and sodium in dairy cows

To determine whether dietary supplementation with clinoptilolite affects the incidence of parturient paresis and serum concentrations of total calcium (tCa), inorganic phosphorus (PO(4) (2)), magnesium (Mg2+), potassium (K+), and sodium (Na+) in dairy cattle. 52 dairy cows. Procedure-Cows were placed into 3 groups. The first 2 groups (group A [n = 17] and group B [17]) were offered a concentrate supplemented with 1.25% and 2.5% clinoptilolite, respectively. The third (group C [n = 18]) served as a control and was offered the concentrate alone. The experiment started 1 month before parturition and lasted until the beginning of the next nonlactating period. Around the time of calving, all cows were monitored for the development of parturient paresis. Blood samples were taken at the commencement of the experiment, on the day of calving, and thereafter at monthly intervals to measure serum tCa, PO(4) (2), Mg2+, K+, and Na+ concentrations. Results-The incidence of parturient paresis in group B cows was significantly lower, compared with group C cows. However, serum concentrations of tCa, P(O4) (2), Mg2+, K+, and Na+ were not significantly affected by long-term supplementation with clinoptilolite. In the context of this experiment, clinoptilolite supplementation at 2.5% appeared to have reduced the incidence of parturient paresis in dairy cows, suggesting that its effectiveness depends on the amount incorporated in the ration of cows. Addition of clinoptilolite in the concentrate of dairy cows during the nonlactating period could be used as a cost-effective preventive treatment for parturient paresis.

Safety of D(‐)‐Lactic Acid Producing Bacteria in the Human Infant

INTRODUCTIONThe gut of human infants is normally rapidly colonized after birth, and this colonization is considered not only to form a protective barrier against pathogenic bacteria but also to direct maturation of the infant immune system (1,2). In recent years, exogenous preparations of probiotic

Neurochemical correlates of differential neuroprotection by long-term dietary creatine supplementation

Dietary supplementation with creatine has proven to be beneficial in models of acute and chronic neurodegeneration. We report here data on the neurochemical correlates of differential protection of long-term creatine supplementation in two models of excitotoxicity in rats, as well as in the mouse model for ALS (G93A mice). In rats, the fall in cholinergic and GABAergic markers due to the excitotoxic death of intrinsic neurons caused by intrastriatal infusion of the neurotoxin, ibotenic acid, was significantly prevented by long-term dietary supplementation with creatine. On the contrary, creatine was unable to recover a cholinergic marker in the cortex of rats subjected to the excitotoxic death of the cholinergic basal forebrain neurons. In G93A mice, long-term creatine supplementation marginally but significantly increased mean lifespan, as previously observed by others, and reverted the cholinergic deficit present in some forebrain areas at an intermediate stage of the disease. In both rats and mice, creatine supplementation increased the activity of the GABAergic enzyme, glutamate decarboxylase, in the striatum but not in other brain regions. The present data point at alterations of neurochemical parameters marking specific neuronal populations, as a useful way to evaluate neuroprotective effects of long-term creatine supplementation in animal models of neurodegeneration.

Effects of dietary magnesium and short-duration transportation on stress response, postmortem muscle metabolism, and meat quality of finishing swine1

Crossbred pigs, heterozygous for the halothane gene, were used to determine the effects of long-term dietary supplementation of magnesium mica (MM) and short-duration transportation stress on performance, stress response, postmortem metabolism, and pork quality. Pigs were blocked by weight, penned in groups (six pigs per pen), and pens (three pens per diet) were assigned randomly either to a control corn-soybean meal diet or the control diet supplemented with 2.5% MM (as-fed basis; supplemented at the expense of corn). Diets were fed during the early-finisher (0.95% lysine, as-fed basis; 43.7 to 68 kg) and late-finisher (0.85% lysine, as-fed basis; 68 to 103 kg) periods. At the conclusion of the 71-d feeding trial, 12 pigs from each dietary treatment were selected randomly and subjected either to no stress (NS) or 3 h of transportation stress (TS). Dietary MM had no effect (P > or = 0.40) on ADG or ADFI; however, G:F was improved (P < 0.05) during the early-finisher period when pigs were fed MM-supplemented diets. Plasma glucose concentrations were increased in TS pigs fed the control diet, but transportation did not affect plasma glucose in pigs fed 2.5% MM (diet x transportation stress; P = 0.02). Dietary MM did not affect blood lactate, cortisol, insulin, NEFA, Ca, or Mg concentrations in response to TS (diet x transportation stress; P > or = 0.13); however, circulating lactate, cortisol, and glucose concentrations increased in TS pigs (transportation stress x time; P < 0.01). The LM from TS pigs fed MM had higher initial (0-min) and 45-min pH values than the LM from NS pigs fed the control diet (diet x transportation stress x time; P = 0.07). Lactic acid concentration and glycolytic potential were greater in the LM of TS pigs fed MM than TS pigs fed control diets (diet x transportation stress; P < or = 0.01). Although some trends were identified, neither MM (P > or = 0.15) nor TS (P > or = 0.11) altered the color or water-holding capacity of the LM and semimembranosus. The transportation model elicited the expected changes in endocrine and blood metabolites, but dietary MM did not alter the stress response in pigs. Conversely, although pork quality traits were not improved by dietary MM, delaying postmortem glycolysis and elevating 0- and 45-min muscle pH by feeding finishing diets fortified with MM may benefit the pork industry by decreasing the incidence of PSE pork in pigs subjected to short-duration, routine stressors.

Trial of probiotics to prevent the vertebral column compression syndrome in rainbow trout (Oncorhynchus mykiss Walbaum)

Two probiotics were tested as alternative treatment to limit the prevalence of the vertebral column compression syndrome (VCCS) in rainbow trout, compared with a preventive treatment with florfenicol. Either the antibiotic, or a lactic acid bacterium, Pediococcus acidilactici, or a yeast, Saccharomyces cerevisiae var. boulardii, was introduced into experimental diets, which were compared with the control diet without supplementation. The antibiotic caused some mortality during the first week after treatment, likely because of the toxicity of the compound. However, this antibiotic treatment limited the occurrence of VCCS to 3%, vs. 13% of fish affected in the control group. Pediococcus acidilactici provided the same level of protection as the antibiotic, but on condition that the treatment was applied during the 5 months of the experiment, without any adverse effect on survival. A treatment with P. acidilactici only during the first 20 days of feeding was not sufficient to limit VCCS, nor was the treatment with the yeast sufficient. These results were discussed while comparing the microbiota associated with the intestine. The experiment reinforced the hypothesis that pathogenic bacteria are involved in VCCS. The long-term dietary supplementation with P. acidilactici seemed promising as a preventive treatment against the syndrome, but large-scale investigation in fish farms will be necessary to confirm its prophylactic relevance.

Effects of a Long-Term Dietary Xylitol Supplementation on Collagen Content and Fluorescence of the Skin in Aged Rats

Background: Dietary xylitol has been shown to increase the amounts of newly synthesized collagen, and to decrease fluorescence of the collagenase-soluble fraction in the skin of both healthy and diabetic rats. As in diabetic rats, a decreased rate of collagen synthesis and increased collagen fluorescence has also been detected in the skin of aged rats. We hypothesize that dietary xylitol supplementation may protect against these changes during aging. Objective: The purpose of the present study was to investigate whether a long-term dietary supplementation can protect against the decrease in the amounts of newly synthesized collagen, and against the increase in fluorescence in the collagenase-soluble fraction in the skin of aged rats. Methods:Twenty-four male Sprague-Dawley rats were used in the study. After weaning, the rats were divided into 2 groups of 12 animals. The rats in the control group were fed a basal RM1 diet, while the rats in the experimental group were fed the same diet supplemented with 10% xylitol. After 20 months, the rats were killed and pieces of skin from their dorsal areas were excised. The thickness of the samples was measured with a micrometer screw gauge. The collagen contents of rat skin were measured as hydroxyproline, and glycosylation as fluorescent intensity of collagen. Statistical significances of the differences between the groups were determined using the unpaired t test. Results: No general side effects were detected in the rats during the experimental period. The skin of the xylitol-fed rats was a little thicker than that of the control rats. The hydroxyproline content of the acid-soluble fraction was significantly greater in the xylitol group as compared to the controls. However, there were no significant differences in the hydroxyproline content of the collagenase-soluble fraction between the groups. The fluorescence of the collagenase-soluble fraction was significantly smaller in the xylitol-fed aged rats than in the aged rats fed the basal diet. Conclusions: The results of this study indicate that xylitol caused an increase in the amount of newly synthesized collagen and a decrease in collagen fluorescence in the skin of aged rats.

Effects of Intrauterine Food Restriction and Long-Term Dietary Supplementation with l-Arginine on Age-Related Changes in Renal Function and Structure of Rats

We have previously demonstrated that restricting intrauterine food by 50% in 3-mo-old rats produced lower nephron numbers and early-onset hypertension, the latter being normalized by L-arginine administration. In 18-mo-old rats, such restriction increased glomerulosclerosis. In this study, we expanded our investigation, evaluating functional, morphologic, and immunohistochemical parameters in intrauterine-food-restricted 18-mo-old rats, either receiving L-arginine (RA18) or not (R18). Age-matched, non-food-restricted controls were assigned to similar groups with L-arginine (CA18) and without (C18). After weaning, L-arginine was given daily for 17 mo. No functional or morphologic changes were observed in C18 rats. The R18 rats developed early-onset hypertension, which persisted throughout the observation period, as well as significant proteinuria from 12 mo on. In RA18 rats, L-arginine decreased both blood pressure levels and proteinuria, and glomerular diameter was significantly smaller than in R18 rats (115.63 +/- 2.2 versus 134.8 +/- 1.0 mum, p < 0.05). However, in RA18 rats, glomerular filtration rate remained depressed. Although L-arginine prevented glomerulosclerosis (R18 = 14%, RA18 = 4%; p < 0.05), glomerular expression of fibronectin and desmin was still greater in RA18 rats than in controls. Our data show that, although L-arginine prevented hypertension and proteinuria, glomerular injury still occurred, suggesting that intrauterine food restriction may be one of the leading causes of impaired renal function in adult life.

Dietary CDP-choline supplementation prevents memory impairment caused by impoverished environmental conditions in rats

We previously showed that dietary cytidine (5')-diphosphocholine (CDP-choline) supplementation could protect against the development of memory deficits in aging rats. In the present study, younger rats exposed to impoverished environmental conditions and manifesting hippocampal-dependent memory impairments similar to those observed in the aging rodents were given CDP-choline, and its effects on this cognitive deficit were assessed. Male Sprague-Dawley rats reared for 3 mo in impoverished (IC) or enriched environmental (EC) conditions concurrently received either a control diet or a diet supplemented with CDP-choline (approximately 500 mg/kg/d). After 3 mo, rats were trained to perform spatial and cued versions of the Morris water maze, and their rates of acquisition and retention were compared. Impoverished rats exhibited a selective deficit in hippocampal-dependent spatial memory which could be ameliorated by feeding them CDP-choline. The CDP-choline had no memory-enhancing effect in enriched rats, nor did it prevent the memory impairment of impoverished rats if the animals consumed it for the initial or final months instead of for the entire 3-mo period. These findings indicate that long-term dietary CDP-choline supplementation can ameliorate the hippocampal-dependent memory impairment caused by impoverished environmental conditions in rats, and suggest that its actions result, in part, from a long-term effect such as enhanced membrane phosphatide synthesis, an effect shown to require long-term dietary supplementation with CDP-choline.

Garlic Inhibits Microsomal Triglyceride Transfer Protein Gene Expression in Human Liver and Intestinal Cell Lines and in Rat Intestine

Epidemiologic studies have suggested that fresh garlic has lipid-lowering activity. Because the microsomal triglyceride transfer protein (MTP) plays a pivotal role in the assembly and secretion of apolipoprotein B (apoB)-containing lipoproteins, we evaluated the effect of garlic on the expression of the MTP gene in vitro in cell lines and in vivo in rats. Fresh garlic extract (FGE) reduced MTP mRNA levels in both the human hepatoma HepG2 and intestinal carcinoma Caco-2 cells in dose-dependent fashion; significant reductions were detected with 3 g/L FGE. Maximal 72 and 59% reductions, respectively, were observed with 6 g/L FGE. To evaluate the in vivo effect of garlic on MTP gene expression, rats were given a single oral dose of fresh garlic homogenate (FGH), with hepatic and intestinal MTP mRNA measured 3 h after dosing. Rats fed FGH had significantly (46% of the control) lower intestinal MTP mRNA levels compared with the control rats, whereas hepatic MTP mRNA levels were not affected. These results suggest a new mechanism for the hypolipidemic effect of fresh garlic. Long-term dietary supplementation of fresh garlic may exert a lipid-lowering effect partly through reducing intestinal MTP gene expression, thus suppressing the assembly and secretion of chylomicrons from intestine to the blood circulation.

Influence of long-term nutrition with different dietary fats on fatty acid composition of heavy pigs backfat

The aim of this study was to assess the influence of long-term fat supplementation on the fatty acid profile of heavy pig adipose tissue. Fifty-four Large White barrows, averaging 25 kg LW, were randomized (matched weights) to one of three isoenergetic diets supplemented with either tallow (TA), maize oil (MO), or rapeseed oil (RO). The fats were supplemented at 3% as fed from 25 to 110 kg LW, and at 2.5 % from 110 kg to slaughtering. Following slaughter at about 160 kg LW, backfat samples were collected from ten animals per treatment and analyzed. Fatty acid composition of backfat closely reflected the fatty acid composition of the supplemented fats. The backfat of pigs fed TA had the highest saturated fatty acid content (SFA) (P<0.01); those fed MO had the highest content in polyunsaturated fatty acid (PUFA) and the lowest in monounsaturated fatty acid (MUFA) content; those fed RO had the highest content of linolenic acid (C18:3) and cis 11-ecosenoic acid (C20:1). Only MO treatment had an effect on linoleic acid levels and the iodine value (IV) of backfat, resulting in levels higher than those (IV = 70; C18:2 = 15%) accepted by the Parma Consortium for dry-cured ham. The IV and unsaturation index in both layers of subcutaneous backfat tissue differed significantly between treatments.These results show that long-term dietary supplementation with different fats changes the fatty acid profile of heavy pig adipose tissue. Supplementation with rapeseed oil increases the proportion of “healthy” fatty acids in pig fat, thereby improving the nutritional quality, however the effects on the technological quality of the fat must be carefully assessed.